There is interest in pharmacologic preconditioning for end-organ protection by targeting the HIF system. This can be accomplished by inhibition of prolyl 4-hydroxylase (PHD). GSK360A is an orally active PHD inhibitor that has been previously shown to protect the failing heart. We hypothesized that PHD inhibition can also protect the brain from injuries and resulting behavioral deficits that can occur as a result of surgery. Thus, our goal was to investigate the effect of pre-stroke surgery brain protection using a verified GSK360A PHD inhibition paradigm on post-stroke surgery outcomes. Vehicle or an established protective dose (30 mg/kg, p.o.) of GSK360A was administered to male Sprague-Dawley rats. Initially, GSK360A pharmacokinetics and organ distribution were determined, and then PHD-HIF pharmacodynamic markers were measured (i.e., to validate the pharmacological effects of the GSK360A administration regimen). Results obtained using this validated PHD dose-regimen indicated significant improvement by GSK360A (30mg/kg); administered at 18 and 5 hours prior to transient middle cerebral artery occlusion (stroke). GSK360A exposure and plasma, kidney and brain HIF-PHD pharmacodynamics endpoints (e.g., erythropoietin; EPO and Vascular Endothelial Growth Factor; VEGF) were measured. GSK360A provided rapid exposure in plasma (7734 ng/ml), kidney (45–52% of plasma level) and brain (1–4% of plasma level), and increased kidney EPO mRNA (80-fold) and brain VEGF mRNA (2-fold). We also observed that GSK360A increased plasma EPO (300-fold) and VEGF (2-fold). Further assessments indicated that GSK360A reduced post-stroke surgery neurological deficits (47–64%), cognitive dysfunction (60–75%) and brain infarction (30%) 4 weeks later. Thus, PHD inhibition using GSK360A pretreatment produced long-term post-stroke brain protection and improved behavioral functioning. These data support PHD inhibition, specifically by GSK360A, as a potential strategy for pre-surgical use to reduce brain injury and functional decline due to surgery-related cerebral injury.

Pilot study on biocompatibility of fluorescent nanodiamond-(NV)-Z800 particles in rats: safety, pharmacokinetics, and bio-distribution (part III) Frank C Barone,1 Cezary Marcinkiewicz,2,3 Jie Li,1 Mark Sternberg,3 Peter I Lelkes,2 Dmitriy A Dikin,4 Peter J Bergold,1 Jonathan A Gerstenhaber,2 Giora Feuerstein3 1Department of Neurology, SUNY Downstate Medical Center, Brooklyn, NY, USA; 2Department of Bioengineering, Temple University, College of Engineering, Philadelphia, PA, USA; 3Debina Diagnostics Inc, Newtown Square, PA, USA; 4Department of Mechanical Engineering, Temple University, Philadelphia, PA, USA Introduction: We hereby report on studies aimed to characterize safety, pharmacokinetics, and bio-distribution of fluorescent nanodiamond particles (NV)-Z~800 (FNDP-(NV)) administered to rats by intravenous infusion in a single high dose. Methods: Broad scale biological variables were monitored following acute (90 minutes) and subacute (5 or 14 days) exposure to FNDP-(NV). Primary endpoints included morbidity and mortality, while secondary endpoints focused on hematology and clinical biochemistry biomarkers. Particle distribution (liver, spleen, lung, heart, and kidney) was assessed by whole organ near infrared imaging using an in vivo imaging system. This was validated by the quantification of particles extracted from the same organs and visualized by fluorescent and scanning electron microscopy. FNDP-(NV)-treated rats showed no change in morbidity or mortality and preserved normal motor and sensory function, as assessed by six different tests. Results: Blood cell counts and plasma biochemistry remained normal. The particles were principally distributed in the liver and spleen. The liver particle load accounted for 51%, 24%, and 18% at 90 minutes, 5 days, and 14 days, respectively. A pilot study of particle clearance from blood indicated 50% clearance 33 minutes following the end of particle infusion. Conclusion: We concluded that systemic exposure of rats to a single high dose of FDNP-(NV)-Z~800 (60 mg/kg) appeared to be safe and well tolerated over at least 2 weeks. These data suggest that FNDP-(NV) should proceed to preclinical development in the near future. Keywords: fluorescent nanodiamond particles, biocompatibility, near infrared imaging, scanning electron microscopy, neurobehavioral function, pharmacokinetics, rat

This chapter will introduce the reader to the pathophysiology of two devastating neurologic events, traumatic brain injury (TBI) and acute ischemic stroke (AIS). Here we focus on the role of key pro-inflammatory and anti-inflammatory cytokines. Several experimental interventions have been found to modulate cytokine production and brain injury after AIS or TBI. Here minocycline, biological response modifiers, hormonal therapies, omega-3 fatty acids, N-acetylcysteine, and cannabinoids will be discussed. In addition, the role of cytokine-induced inflammasomes in both TBI and AIS will be addressed and followed by discussion of pro-inflammatory cytokines (e.g., TNF-α, IL-1β, IL-18, and IFN-γ). Finally, the main anti-inflammatory cytokines, IL-33, IL-10, IL-6, and IL-4, will be discussed in the context of both TBI and AIS. It should be noted that the role of these cytokines is diverse and the dichotomization of classically pro-versus anti-inflammatory cytokines is being re-examined, as many of these cytokines have been found to play dual roles in TBI and AIS brain injury.

Background: Thromboembolic events are a major cause of heart attacks and strokes. However, diagnosis of the location of high risk vascular clots is hampered by lack of proper technologies for their detection .We recently reported on bio-engineered fluorescent diamond-(NV)-Z~800nm (FNDP-(NV)) conjugated with bitistatin (Bit) and proven its ability to identify iatrogenic blood clots in the rat carotid artery in vivo by Near Infra-Red (NIR) monitored by In Vivo Imaging System (IVIS). Purpose: The objective of the present research was to assess the in vivo biocompatibility of FNDP-(NV)-Z~800nm infused intravenously to rats. Multiple biological variables were assessed along this 12 week study commissioned in anticipation of regulatory requirements for a long-term safety assessment. Methods: Rats were infused under anesthesia with aforementioned dose of the FNDP-(NV), while equal number of animals served as control (vehicle treated). Over the 12 week observation period rats were tested for thriving, motor, sensory and cognitive functions. At the termination of study, blood samples were obtained under anesthesia for comprehensive hematology and biochemical assays. Furthermore, 6 whole organs (liver, spleen, brain, heart, lung and kidney) were collected and examined ex vivo for FNDP-NV) via NIR monitored by IVIS and histochemical inspection. Results: All animals survived, thrived (no change in body and organ growth). Neuro-behavioral functions remain intact. Hematology and biochemistry (including liver and kidney functions) were normal. Preferential FNDP-(NV) distribution identified the liver as the main long- term repository. Certified pathology reports indicated no outstanding of finding in all organs. Conclusion: The present study suggests outstanding biocompatibility of FNDP-(NV)-Z~800nm after long-term exposure in the rat.

The choice of an animal model for cerebrovascular research is often determined by the disease subtype to be studied (e.g. ischemic stroke, hemorrhage, trauma), as well as the nature of the intervention to be tested (i.e. medical device or pharmaceutical). Many initial studies are performed in smaller animals, as they are cost-effective and their encephalic vasculature closely models that of humans. Non-human primates are also utilized when confirmation or validation is required on higher levels and to test larger devices. However, working with primates is complex and expensive. Intermediate sized animal models, such as swine and sheep, may represent a valuable compromise. Their cerebrovascular anatomy, however, comes with challenges because of the natural higher external carotid artery perfusion and the existence of a rete mirabile. We describe a modification to the traditional swine cerebrovascular model that significantly enhances selective brain hemispheric perfusion, limiting external carotid perfusion and dilution. We investigated whether unilateral endovascular coil-embolization of external carotid artery branches in swine would lead to increased brain perfusion, altering cerebral circulation so that it more closely models human cerebral circulation. Equal amounts of approximately 4 °C cold saline were injected in 6 Yorkshire pigs into the ipsilateral common carotid artery before and after embolization. Hemispheric temperature changes from pre- and post-embolization were obtained as a measure of brain perfusion and averaged and compared using non-parametric statistical tests (Wilcoxon signed rank test, Mann–Whitney U Test). Graphs were plotted with absolute changes in hemispheric temperature over time to determine peak temperature drop (PTD) and corresponding time to peak (TTP) following the cold bolus injection. There was a 288 ± 90 % increase in ipsilateral brain cooling after embolization indicating improved selective blood flow to the brain due to this vascular modification. We have developed an effective, selective vascular brain model in swine that may be useful as a practical and cost-reducing intermediate step for evaluating target dose–responses for central nervous system drugs and brain selective interventions, such as local hypothermia.